Japanese Patent Application Laid-open No. 2004-114913 (hereinafter, “patent document 1”) discloses a conventional air conditioner for a vehicle of this kind. According to the patent document 1, in an air conditioning unit 101 of the air conditioner 100 for a vehicle, a blower 103, an evaporator 104, an air mix door box 105, and a heater core 106 are arranged in an inside draft duct 102 in this order from the upstream side in an air-blowing direction as shown in FIG. 1. A portion of the draft duct 102 downstream from the position of the air mix door box 105 (upstream position of the heater core 106) is divided into three in a direction orthogonal to the air-blowing direction. These three divided passages are a left passage for a left front seat, a right passage for a right front seat, and a central passage for a back seat. FIG. 1 is a sectional view at a position of the passage for the left front seat.
As shown in FIG. 2, the air mix door box 105 includes three air mix doors 110a (not shown, not shown) corresponding to the three divided passages, and pairs of upper and lower openings 111a, 111b, 112a, 112b, 113a, and 113b corresponding to the air mix doors 110a (not shown, not shown), respectively. Air is distributed to a warm air passage 114a (not shown, not shown) passing through the heater core 106 and a cool air passage 115a (not shown, not shown) bypassing through the heater core 106 at a desired ratio. The three air mix doors 110a (not shown, not shown) can be driven independently from each other.
Air mix areas ME1 (not shown, not shown) are formed downstream of a warm air passage 114 (not shown, not shown) and a cool air passage 115 (not shown, not shown) of the three divided passages, respectively, and unit blow openings are formed at locations facing the air mix areas ME1 (not shown, not shown). The left front-seat passage is provided with unit blow openings 120, 121, and 122, and selection doors 123, 124, and 125.
In the above-described structure, air that passed through the evaporator 104 is branched into the left front-seat passage, the right front-seat passage, and the back seat passage. The branched air passes through the warm air passage 114a (not shown, not shown) and the cool air passage 115a (not shown, not shown) according to the respective air-distribution ratios of the air mix doors 110a (not shown, not shown). Warm air from the warm air passage 114a (not shown, not shown) and cool air from the cool air passage 115a (not shown, not shown) joins together in the air mix areas ME1 (not shown, not shown), resulting in air heated or cooled to a desired temperature, respectively. Conditioned air having the desired temperature is sent out into the vehicle room through a selected unit blow opening in each passage (unit blow opening 120 in the left front-seat passage (or 121 or 122)). In this way, the air conditioner operations are independently carried out in the front seat left area, the front seat right area, and the back seat area in the vehicle room.
In the conventional example, drive systems of the three air mix doors 110a (not shown, not shown) are constituted in the following manner.
The drive system of the left air mix door 110a for the left front seat includes a rack (not shown) provided on the air mix door 110a, a drive gear 130 that meshes with the rack (not shown), and a first support shaft 131 that supports the drive gear 130 and that projects outward from a left wall 105a of the air mix door box 105. The drive system transmits torque of a first actuator (not shown) via the first support shaft 131.
The drive system of the right air mix door (not shown) for the right front seat includes a rack (not shown) provided on the air mix door (not shown), a drive gear (not shown) that meshes with the rack (not shown), and a second support shaft (not shown) that supports the drive gear (not shown) and projects outward from a right wall (not shown) of the air mix door box 105. The drive system transmits torque of the second actuator (not shown) via this second support shaft (not shown).
The drive system of the central air mix door (not shown) for the back seat includes a rack (not shown) provided on the air mix door (not shown), a drive gear 132 that meshes with the rack (not shown), and a third support shaft 133 that supports the drive gear 132 and that projects outward from a left wall 105a (or right wall) of the air mix door box 105 at a location deviated from the first support shaft 131 and the second support shaft (not shown). The drive system transmits torque of a third actuator (not shown) via the third support shaft 133.
Here, the first support shaft 131 and the second support shaft (not shown) located at left and right positions can be located on the same axis, but the central third support shaft 133 cannot be located on the same axis. Thus, the central drive gear 132 meshes with the rack (not shown) at a location shifted vertically from the left and right drive gears 130 and (not shown), and the third support shaft 133 is shifted vertically from the first and second support shafts 131 and (not shown).
In the conventional air conditioner 100 for a vehicle, the three drive gears 130, (not shown), and 132, and their support shafts 131, (not shown), and 133 are located not on the same axis but at the vertically shifted positions. Therefore, the air mix doors 111a and (not shown) at the left and right positions, the corresponding pairs of upper and lower openings 111a, 111b, 113c, and 113b, the central air mix door (not shown), and the corresponding pair of upper and lower openings 112a and 112b are also located at the vertically shifted positions accordingly. Thus, there is a problem in that vertical sizes of the air mix door box 105 and thus the air conditioner 100 for a vehicle are increased.
Hence, it is an object of the present invention to provide an air conditioner for a vehicle having a reduced size and being capable of independently carrying out air conditioning operations in a plurality of areas in a vehicle room.